Last month, we wrote about the tale of two Washingtons: just a day after 41 Republican Senators in Washington, DC prevented a federal minimum wage increase to $10.10 from even being debated, Seattle, Washington announced a plan to raise its minimum wage to $15 per hour.

On Tuesday, the city made that deal official, with the city council voting unanimously to approve a $15 minimum wage. It will be phased in over the next seven years and will be the highest in the United States.

The minimum wage has been advancing in cities and states around the country, and not the halls of Congress, for some time. But the ambition of Seattle’s increase has sparked a particular flame for other cities and states considering a bigger increase. The Seattle Timesreports that “organizers who pushed a $15 minimum wage in Seattle are looking at their next targets,” including Bellevue, Spokane, or an increase in the state minimum wage.

“It’s expanding the range of the possible,” said Paul Sonn, general counsel and program director for the National Employment Law Project. “Seattle was a breakthrough.”

Think Progress, meanwhile, has published a detailed investigative report on the fight to bring a living wage to Seattle, featuring a coalition of a millionaire, a socialist, and some Taco Bell workers. While it notes that “some things about that process may be unique to Seattle,” the ingredients for a $15 minimum wage “are completely portable, and could soon come to a city near you.”

At the same time, the ambition of Seattle’s increase — a full-time minimum wage worker making $15 per hour will earn over $30,000 annually — has generated broader discussion among national thought leaders and policy analysts. The Seattle entrepreneur and venture capitalist Nick Hanauer, a prominent supporter of the $15 campaign, spells out the argument in favor of the increase in a New York Times column entitled “Well Paid Workers Strengthen Local Economies“:

If the minimum wage had tracked productivity gains since 1968, it would be $21.70 today; had it tracked the wages of us in the top 1 percent, it would be $28. Raising it to only $15 in a city as prosperous and expensive as Seattle isn’t a risky experiment. The risky experiment has been the 30 years of trickle-down policy that enriched a few of us while eviscerating the middle class.

The most insidious part of trickle down isn’t the idea that if the rich get richer, that’s good for the economy. It is that if the poor get richer, that will be bad for the economy. A $15-an-hour wage isn’t a risky and untried policy in Seattle. It is the natural evolution of common-sense economic thinking.

BOTTOM LINE: Conservatives really believe that the economy grows from the top down – that if we give more to CEOs and billionaires it will trickle down to the rest of us. But decades of trickle down policy has done nothing but give millionaires and billionaires more, leaving middle and worker class families with less and destabilizing our entire economy. Seattle’s $15 minimum wage is a bold alternative approach–one that will help the economy grow from the middle class out and build an economy that works for everyone, not just the wealthy few. And it appears that the wave could be catching on.